Largest structure in universe found — and it's mind-bogglingLarge quasar group stretches 4 billion light-years; theory says it shouldn't exist

Astronomers have discovered the largest known structure in the universe, a clump of active galactic cores that stretches 4 billion light-years from end to end.The structure is a large quasar group (LQG), a collection of extremely luminous galactic nuclei powered by supermassive central black holes. This particular group is so large that it challenges modern cosmological theory, researchers said."While it is difficult to fathom the scale of this LQG, we can say quite definitely it is the largest structure ever seen in the entire universe," lead author Roger Clowes, of the University of Central Lancashire in England, said in a statement. "This is hugely exciting, not least because it runs counter to our current understanding of the scale of the universe."Quasars are the brightest objects in the universe. For decades, astronomers have known that they tend to assemble in huge groups, some of which are more than 600 million light-years wide.But the record-breaking quasar group, which Clowes and his team spotted in data gathered by the Sloan Digital Sky Survey, is on another scale altogether. The newfound LQC is composed of 73 quasars and spans about 1.6 billion light-years in most directions, though it is 4 billion light-years across at its widest point.To put that mind-boggling size into perspective, the disk of the Milky Way galaxy — home of Earth's solar system — is about 100,000 light-years wide. And the Milky Way is separated from its nearest galactic neighbor, Andromeda, by about 2.5 million light-years.The newly discovered LQC is so enormous, in fact, that theory predicts it shouldn't exist, researchers said. The quasar group appears to violate a widely accepted assumption known as the cosmological principle, which holds that the universe is essentially homogeneous when viewed at a sufficiently large scale.Calculations suggest that structures larger than about 1.2 billion light-years should not exist, researchers said."Our team has been looking at similar cases which add further weight to this challenge, and we will be continuing to investigate these fascinating phenomena," Clowes said.The new study was published Friday in the Monthly Notices of the Royal Astronomical Society.

Astronomers have finally solved a longstanding cosmic mystery — why a super-dense gas cloud near our Milky Way galaxy's core isn't churning out many new stars.The gas cloud, known as G0.253+0.016, is simply swirling too fast, researchers said. And it lacks the requisite pockets of even denser material, which eventually collapse under their own gravity to form stars.The results suggest that star formation is more complex than astronomers had thought and may help them better understand the process, researchers said.An oddly barren cloud G0.253+0.016, which is about 30 light-years long, defies the conventional wisdom that dense gas glouds should produce lots of stars.The cloud is 25 times more dense than the famous Orion Nebula, which is birthing stars at a furious rate. But only a few stars are being born in G0.253+0.016, and they're pretty much all runts."It's a very dense cloud and it doesn't form any massive stars, which is very weird," study lead author Jens Kauffmann, of Caltech in Pasadena, said in a statement.Kauffmann and his colleagues determined to find out why. Using the Submillimeter Array, a set of eight radiotelescopes atop Mauna Kea in Hawaii, they found that G0.253+0.016 possesses very few ultra-dense nuggets that could collapse to form stars."That was very surprising," said co-author Thushara Pillai, also of Caltech. "We expected to see a lot more dense gas."Spinning out of control The researchers then probed the cloud with another network of telescopes, the Combined Array for Research in Millimeter-wave Astronomy in California.CARMA data showed that gas within G0.253+0.016 is zipping around 10 times faster than gas in similar clouds. G0.253+0.016 is on the verge of flying apart, with its gas churning too violently to coalesce into stars.Further, the team found that the cloud is full of silicon monoxide, a compound typically produced when fast-moving gas smashes into dust particles. The abnormally large amounts of silicon monoxide suggest that G0.253+0.016 may actually consist of two colliding clouds, whose impact is generating powerful shockwaves."To see such shocks on such large scales is very surprising," Pillai said.G0.253+0.016 may eventually be able to churn out stars. But its position near the center of the Milky Way could make it tough for the cloud to settle down, as it may smash into other clouds or be ripped apart by the immense gravitational pull near the galaxy's central black hole, researchers said.The study has been accepted for publication in the Astrophysical Journal Letters. The team also presented the results last week at the 221st meeting of the American Astronomical Society in Long Beach, Calif.

A huge storm at Saturn's north pole is 20 times larger and 4 times as powerful as storms on Earth.

Images of the storm, the eye of which measures more than 1250 miles across, were captured by NASA's orbiting Cassini spacecraft. Of particular interest to scientists is the fact that the storm bears a close resemblance to storms we see on the Earth, albeit on a different scale. The hurricane is located within a strange six-sided weather pattern on Saturn known as "The Hexagon".

Saturn isn't the only place in the solar system where large storms have been observed. On Jupiter, a vast storm known as 'The Great Red Spot' has been churning for up to several hundred years. The violent maelstrom is so large that it covers a region big enough to encompass three planets the size of the Earth.

A huge storm at Saturn's north pole is 20 times larger and 4 times as powerful as storms on Earth.

Images of the storm, the eye of which measures more than 1250 miles across, were captured by NASA's orbiting Cassini spacecraft. Of particular interest to scientists is the fact that the storm bears a close resemblance to storms we see on the Earth, albeit on a different scale. The hurricane is located within a strange six-sided weather pattern on Saturn known as "The Hexagon".

Saturn isn't the only place in the solar system where large storms have been observed. On Jupiter, a vast storm known as 'The Great Red Spot' has been churning for up to several hundred years. The violent maelstrom is so large that it covers a region big enough to encompass three planets the size of the Earth.

A new study has demonstrated that plants can use an underground network of fungi to warn each other about incoming insect attacks.

Carried out by researchers from the University of Aberdeen, the James Hutton Institute and Rothamsted Research, the study demonstrated that the plants are able to send warnings of incoming aphids to other plants connected to their network. The plants then send out a chemical signal that repels aphids and attracts wasps, a natural aphid predator.

The research follows previous findings that have shown plants can communicate similar chemical warnings through the air.

The new study says plants can connect with other via a common fungus known as mycorrhizae. "Mycorrhizal fungi need to get [products of photosynthesis] from the plant, and they have to do something for the plant," John Pickett of Rothamsted Research told the BBC.

"In the past, we thought of them making nutrients available from the [roots and soil], but now we see another evolutionary role for them in which they pay the plant back by transmitting the signal efficiently," he said.University of Aberdeen’s David Johnson added, "Our understanding of ecological systems has not considered the fact that plants are interconnected in this way. It could have major implications for our understanding of how one organism affects another."

Conversely, the plants in the study not connected to the fungal network did not send out warning signals to other plants after coming under attack. The in-network plants were also covered with bags to ensure that they were not actually sending the signals through the air.

Pickett said the discovery could lead to farms using the fungi as an advance warning system for their crops. In theory, one “sacrificial” plant would be kept at a distance from the crops. If it fell under attack from insects, it would warn the rest of the plants, giving them time to mount a viable defense.

A new study has demonstrated that plants can use an underground network of fungi to warn each other about incoming insect attacks.

Carried out by researchers from the University of Aberdeen, the James Hutton Institute and Rothamsted Research, the study demonstrated that the plants are able to send warnings of incoming aphids to other plants connected to their network. The plants then send out a chemical signal that repels aphids and attracts wasps, a natural aphid predator.

The research follows previous findings that have shown plants can communicate similar chemical warnings through the air.

The new study says plants can connect with other via a common fungus known as mycorrhizae. "Mycorrhizal fungi need to get [products of photosynthesis] from the plant, and they have to do something for the plant," John Pickett of Rothamsted Research told the BBC.

"In the past, we thought of them making nutrients available from the [roots and soil], but now we see another evolutionary role for them in which they pay the plant back by transmitting the signal efficiently," he said.University of Aberdeen’s David Johnson added, "Our understanding of ecological systems has not considered the fact that plants are interconnected in this way. It could have major implications for our understanding of how one organism affects another."

Conversely, the plants in the study not connected to the fungal network did not send out warning signals to other plants after coming under attack. The in-network plants were also covered with bags to ensure that they were not actually sending the signals through the air.

Pickett said the discovery could lead to farms using the fungi as an advance warning system for their crops. In theory, one “sacrificial” plant would be kept at a distance from the crops. If it fell under attack from insects, it would warn the rest of the plants, giving them time to mount a viable defense.

It's 1.7 miles long. Its surface is covered in a sticky black substance similar to the gunk at the bottom of a barbecue. If it impacted Earth it would probably result in global extinction. Good thing it is just making a flyby.

Asteroid 1998 QE2 will make its closest pass to Earth on May 31 at 1:59 p.m. PDT.

Scientists are not sure where this unusually large space rock, which was discovered 15 years ago, originated from. But the mysterious sooty substance on its surface could indicate it may be the result of a comet that flew too close to the sun, said Amy Mainzer, who tracks near-Earth objects at Jet Propulsion Laboratory in La Cañada Flintridge. It might also have leaked out of the asteroid belt between the orbits of Mars and Jupiter, she said.

We will know more after the asteroid zips closer to Earth and scientists using the Deep Space Network antenna in Goldstone, Calif., and the Arecibo Observatory in Puerto Rico can get a better look at it. Astronomers at both observatories plan to track it closely from May 30 to June 9, according to a JPL release.

At its closest approach the asteroid will still be 3.6 million miles from our planet (about 15 times the distance between the Earth and the moon), but it will be close enough for these powerful radar antennas to see features as small as 12 feet across.

"With radar we can transform an object from a point of light into a small world with its own characteristics," Lance Benner, JPL's principal investigator for Goldstone radar observations, said in a statement.

There is no chance that asteroid 1998 QE2 could collide with Earth this go-around, and its next close approach won't be until 2119.

Still, Mainzer said the size of the asteroid, and its potential for mass destruction, should remind us that there are some scary things flying around in space.

"This is a really big asteroid, similar in size to the one that killed off the dinosaurs, and it's getting very close to us," she said. "Fortunately we've been tracking its orbit very carefully so we know with great certainty it won't hit us.

We've had a really large amount of 'fly bys' by extinction level asteroids the last few years. More than I remember being mentioned before. I wonder if the one with our name on it is on its way?It's only a matter of galactic time before it arrives. How much will that be in human years though?